1. Technical Field
The present invention relates to a liquid ejecting head and a liquid ejecting apparatus and, particularly, relates to an ink jet type recording head and an ink jet type recording apparatus which eject ink as liquid.
2. Related Art
Recently, a liquid ejecting head in which a pressure of liquid in a pressure generation chamber is changed by an actuator device, such as a piezoelectric element, and thus the liquid droplets is ejected through nozzles communicating with the pressure chamber has been known. An ink jet type recording head which ejects ink droplets as liquid droplets is a representative example of the liquid ejecting head described above.
The ink jet type recording head includes a piezoelectric element on one surface side of a flow-path forming substrate in which a pressure generation chamber communicating with nozzle openings is provided. In the ink jet type recording head, a diaphragm is deformed by driving the piezoelectric element, and thus a pressure in the pressure generation chamber is changed. Therefore, ink droplets are ejected through the nozzles (see JP-A-2009-172878, for example).
In some cases, the diaphragm is bent toward the piezoelectric element side or the pressure generation chamber side when voltage is not applied to the piezoelectric element. Such an initial bent state of the piezoelectric element is caused by various factors, such as a manufacturing process and a forming material.
A bent state of the diaphragm when the piezoelectric element is operated and the diaphragm is deformed to the maximum extent is set to a reached bent state. A difference between a reached bent amount and an initial bent amount is set to a displacement amount.
The greater the initial bent amount of the diaphragm is, the greater the reached bent amount of the diaphragm owing to the piezoelectric element is. However, in this case, a displacement amount does not significantly increase. As described above, the displacement amount does not significantly increase as much as the reached bent amount increasing owing to the deformation of the piezoelectric element. Thus, there is a problem in that efficiency of energy applied to the piezoelectric element is poor, compared to the displacement amount due to the piezoelectric element.
Such a problem is not limited to the ink jet type recording head but common to a liquid ejecting head which ejects liquid other than ink.